A coroner says a Department of Conservation volunteer likely slipped on rocks, fell into the sea and drowned at Raoul Island.
It was thought Mihai Muncas-Nagy died in January 2012 after being swept off the rocks, while checking ocean temperatures.
Mr Muncas-Nagy was last seen on New Year's Day when he told colleagues he was going to bed early as he had to check the water temperature at Fishing Rock at 6am the following day.
When he did not return by 10am, his colleagues went looking. His car was found by the rock, the equipment shed was open and the temperature gauge was floating.
Coroner Brandt Shortland said he probably slipped on the rocks and fell into the water.
He said he is pleased and satisfied that as a result of the death, the use of a locator beacon and gps are compulsory.
DoC admitted health and safety failings and paid $60,000 in reparations.